On Mon, Nov 16, 2020 at 6:01 AM Martin Schiller <ms@xxxxxxxxxx> wrote: > > This makes it possible to handle carrier loss and detection. > In case of Carrier Loss, layer 2 is terminated > In case of Carrier Detection, we start timer t1 on a DCE interface, > and on a DTE interface we change to state LAPB_STATE_1 and start > sending SABM(E). > + lapb_dbg(0, "(%p): Carrier detected: %s\n", > + dev, dev->name); > + if (lapb->mode & LAPB_DCE) { > + lapb_start_t1timer(lapb); > + } else { > + if (lapb->state == LAPB_STATE_0) { > + lapb->state = LAPB_STATE_1; > + lapb_establish_data_link(lapb); > + } > + } Do you mean we will now automatically establish LAPB connections without upper layers instructing us to do so? If that is the case, is the one-byte header for instructing the LAPB layer to connect / disconnect no longer needed?